Broad Autism Phenotype (BAP) - Personality Styles and Preferences in a Sample of Portuguese Families of Children with Autism Spectrum Disorders

Background: The current researches have been pointing to the study of families of children with autism spectrum disorders (ASD) in order to identify a broad autism phenotype (BAP). The BAP is a set of personality and language characteristics that reflect the phenotypic expression of autism, in non-autistic relatives of autistic individuals. Social Responsiveness Scale (SRS) and the Broad Autism Phenotype Questionnaire (BAPQ), are the two most used scales to check this phenotypic expression.

Objectives: To characterize the BAP in a sample of Portuguese families, where one child has ASD and an unaffected sibling, to identify the autism traits in parents and unaffected siblings.

Methods: The sample consists of 95 families (proband, his parents and the unaffected sibling closest in age to the proband). Family inclusion criteria were: (1) one child with ASD - ADI-R positive and ADOS (positive for autism or ASD); (2) one unaffected sibling (negative result on SCQ). To assess the BAP: (1) both parents completed the BAPQ about themselves and about their partners; (2) BAPQ was completed for siblings aged >16 years, by themselves and by their parents (3) the SRS was completed by parents about the proband, the sibling and about their partner.

Statistic analysis was performed comparing the different results of the scales with Mann-Whitney test for unpaired samples (σ)=0.05, p<0.05.

Results: 95 families: 92M/3F probands, 100 months of median age.

On the BAPQ self-report, relative to published norms, parents exceeded cut-off scores for Aloof Personality (AP), for Pragmatic Language deficits (PRD), for Rigid Personality (RP) and for Total scale, respectively in 40 (21%), 49 (26%), 91 (48%) and 34 parents (18%); indicating that parents had multiple features of the BAP.

However, on the parents BAPQ informant report the percentages of abnormalities were lower than that observed in the self report view. Actually for parents cut-off scores were exceeded only in 16 (8%) for AP, 42 (22%) for PLD, 35 (18%) for RP and in 18 (9%) for Total scale.

Regarding to the results of the siblings (n=18) on the BAPQ self and informant report, 3 subjects (17%) exceeded cut-off scores in AP, PLD and Total. In the RP more siblings had exceeded cut-off scores in subject’s report (n=7, 39%) than in informant (n=2, 11%).

Comparing parents self and informant report, we found significant differences in personalities traits between fathers and mothers. Fathers are more aloof (p<.03) and mothers more rigid (p<.02). Moreover in general fathers demonstrate more BAP characteristics (p<.01).

Relative to SRS, 47 parents (25%), 59 siblings (62%) and 90 probands (95%) exceeded cut-off for ASD traits total score ≥60. Comparing mother, father and siblings, there are significant differences (p<.028).

Conclusions: We found a remarkable percentage of fathers and mothers with autistic traits especially in the self report view. In general fathers demonstrated more autistic personality, mainly aloof type. Mothers are more rigid. Worrying is that in the SRS more than a half of the “unaffected” siblings exceeded the cut-off for pathology. These findings should be replicated in a larger sample and compared with families without autistic cases.